Some known vehicles have cast subframes disposed on vehicle frames, and torque rods connected to widthwise centers of the subframes. The widthwise center is hereinafter referred to as “connecting portion” of the subframe. Through the torque rod connected to the subframe, the subframe supports a vehicular power plant.
The power plant is, for example, an engine/transmission unit, that is, an integrated engine and transmission.
The subframe has a hollow shape formed by a core placed in a cavity of a mold during casting. The subframe is light due to the hollow shape (see, e.g., patent literature 1 below)
For the subframe disclosed in patent literature 1, however, a relatively large load is applied from the torque rod to the connecting portion of the subframe because the connecting portion supports the power plant through the torque rod.
Thus, the connecting portion needs to be thick enough to obtain rigidity/strength, which makes it difficult to lighten the subframe.